Lupus is a systemic autoimmune disease that is complex in genetics and its immunological origins. Renal disease is a leading cause of morbidity and mortality in lupus, particularly among minority women. Although serial renal biopsies may be ideal in closely monitoring the progression of lupus nephritis, it may not be practical or feasible. Hence, the long-term goal of these studies is to identify potential biomarkers that may be of use in monitoring the progression of renal disease in lupus. Using different proteomic approaches, we have uncovered several molecules that appear in the urine during antibody-mediated nephritis. Our completed cross-sectional studies have helped uncover 6 potential biomarker candidates in the urine of mice and patients with lupus. In this proposal, we will study a cohort of lupus patients, 90% of whom are minority individuals, in a longitudinal fashion in order to determine if any of the urinary biomarker candidates might be better at predicting flares, severe histological nephritis, or end stage renal disease, compared to currently used laboratory yardsticks. In addition, we propose to establish the specificity of these biomarkers for lupus nephritis, as well as other causes of proteinuria and nephritis. Given the high incidence of end stage renal disease in lupus, early diagnosis and prompt treatment is absolutely essential. Identification of more predictive biomarkers in the urine of these patients could have a profound impact on the clinical management of lupus nephritis.